The invention relates to a monitoring system for monitoring sleep disordered breathing (SDB).
Sleep disordered breathing (SDB) adversely affects the systemic circulation (hypertension), the pulmonary circulation (pulmonary hypertension) and the myocardium (systolic and diastolic heart failure). Continual management of the SDB disorder is part of the overall management strategy for cardiac disease. The SDB burden is an under observed disorder and rarely quantified, because apnea and hypopnea episodes occur at night and out of the clinical setting.
Therefore there is a need for an automatic monitor of the SDB burden that would permit the clinician to manage the SDB risk factor.
Known solutions monitor the intra-thoracic impedance as a proxy for successful ventilation, (respiratory frequency and tidal volume). The clinical impact of the proxy impedance measurement with respect to the patient's cardiovascular system is not measured and can only be inferred by using epidemiological clinical studies.
Three and four intra-thoracic electrode measurements contain thoracic information, e.g. breathing effort and minute ventilation, as well as heart specific information.
Intra-thoracic impedance measurements often cannot detect obstructive apnea, due to the persistence of thoracic and abdominal breathing effort.